The present invention relates generally to reformable materials, and more specifically to mixtures, primarily solid/liquid mixtures, that can be formed into desired shapes and then re-used to form other desired shapes. The desired shapes may be end products, or may be templates or tools used to form end products or other templates or tools.
The prior art for making molds or tooling deals for the most part with fabricating, machining, layered deposition forming, molding or casting of tools for a single dedicated purpose. While the tools may be modified or the materials recycled, often this is accomplished only with multiple steps and at considerable expense. Specific instances of quickly reformable molds have been found that rely on beads, sand or other particulate materials being blown or poured into a container with at least one flexible or elastically extensible surface. An article is pushed against or surrounded by the flexible surface and the contained particulate material, and then a vacuum is pulled on the container to remove air so that ambient air pressure consolidates the beads or particles and holds the flexible surface against them in the shape of the article. Likewise, numerous instances have been found of cushions, pads or seats that rely on introducing or vacuuming air from a bead-filled, flexible or stretchable sealed envelope, while other instances have been found of reformable shapes comprising flexible envelopes that contain mixtures of beads or microspheres combined with binding yet flowable lubricants or highly viscous materials. Some of these shapes have been made temperature responsive, so that heat would soften them and cooling would harden them.
The following U.S. patents relate to casting, molding, and fabrication:                U.S. Pat. No. 2,517,902 (Luebkeman);        U.S. Pat. No. 3,962,395 (Hägglund);        U.S. Pat. No. 4,931,241 (Freitag);        U.S. Pat. No. 5,198,167 (Ohta et al.);        U.S. Pat. No. 5,262,121 (Goodno);        U.S. Pat. No. 5,348,070 (Fischer et al.);        U.S. Pat. No. 5,374,388 (Frailey);        U.S. Pat. No. 5,928,597 (Van Ert et al.);        U.S. Pat. No. 5,957,189 (Uzaki et al.);        U.S. Pat. No. 5,971,742 (McCollum); and        U.S. Pat. No. 6,224,808 (Essinger et al.).        
The following U.S. patents relate to formable objects of use:                U.S. Pat. No. 3,608,961 (Von Heck);        U.S. Pat. No. 4,327,046 (Davis et al.);        U.S. Pat. No. 4,885,811 (Hayes);        U.S. Pat. No. 4,952,190 (Tarnoff et al.);        U.S. Pat. No. 5,093,138 (Drew et al.);        U.S. Pat. No. 5,556,169 (Parrish et al.);        U.S. Pat. No. 5,881,409 (Pearce); and        U.S. Pat. No. 5,966,763 (Thomas et al.).        